1. Field of the Invention
This invention relates to windows, both plural-hung and single sash types and more particularly to an improved balance assembly for windows of this type.
Single and double-hung windows having balance assemblies are well known and in use. Such windows have been made removable from a window casing. The prior patent of Henry J. Taylor and Maurice E. Sterner, Jr., U.S. Pat. No. 3,676,956 dated July 18, 1972 shows one version of such a window construction. That particular construction related to a removable window and was applicable to single and double-hung windows and was particularly adapted to the use of metal window and sash construction. It provided a simplified and improved design of a window which incorporated a balance assembly and in which both sash may be readily removable without translational movement of the same. Further, it provided an improved structure whereby the sash may be moved in any position in the window casing and further provided for a substantially rigid guiding mounting of the sash within the casing. It further provided an improved and simplied weather-stripping of the window sash in the window casing from the outside toward the inside sealing both sides of each sash surfaces for all positions of movement to effectively weather-strip the window. It further required no special latches and permitted a simplified and easy removal of the window.
2. Summary of the Invention
The present invention provides a novel balance assembly for windows which permits smooth operation of the window and avoids certain dangerous conditions inherent in prior art window balance assemblies. In the prior art window constructions, the balance assemblies have used a coil spring which was attached to a multiple pulley assembly. The pulley assembly operated with a sash cord which could break. The great tension applied to the sash cord by the coil spring could cause a violent release of the pulley assembly and cause damage to the window when the sash cord breaks.
It further provides a simple way to increase or decrease the tension without having to keep a large inventory of different springs available. This is accomplished by the fact that a gas pressurized cylinder is used in place of a coil spring and the gas pressure in the cylinder can be easily varied.
Further, by moving a securing bolt or pin from one set of pulley wheels to another, the balance ratio changes and the output tension can be easily increased or decreased.
The balance assembly can be easily adapted for use with windows having different weights because of the ease of adjustment of the output tension.
The present invention provides closure caps which can be easily snapped in place after the sash cord has been laced around the exposed pulleys to make lacing easy. The closure caps then prevent the sash cord from coming out of the pulley wheel grooves.
The present invention also provides a slot in one of the closure caps through which the sash cord leaves the balance assembly. The slot is made narrow so that the connector on the end of the sash cord cannot be drawn back into the balance assembly.